B SERIES Photo-Electric Light Curtain Systems

Transcription

1 B SERIES TECHNICAL MANUAL Release 10/01/98, ver. 2.0 B SERIES Photo-Electric Light Curtain Systems WARNING Guardstar by Tapeswitch photo-electric safety systems are intended to protect operators working at or near dangerous machinery. They can only perform this function if they are correctly fitted to a suitable machine. It is essential that the full contents of this manual and all the international documents referred to herein are fully understood before any attempt at installation is made. If in doubt contact Tapeswitch Corporation. IMPORTANT This manual must accompany the product throughout its working life. Those persons responsible for the product must ensure that all persons involved in the installation, commissioning, operation, maintenance and servicing of the product have access to all the information supplied by the manufacturers of the machine and its safety system. 1

2 1. GENERAL CONTENTS Page 1.1 INTRODUCTION PRODUCT APPLICATION Typical Applications Suitability PRODUCT STANDARDS PRODUCT FEATURES Safety Integrity Ease of Installation Protection from Environment PRODUCT RANGE General Detection Capability Protected Heights Accessories Mirror Units Mounting Stands ORDERING INFORMATION Light Curtains Cable Options Interface and Programming Units 9 2. TECHNICAL DESCRIPTION 2.1 CURTAIN COMMUNICATIONS TEST INPUT INDICATORS INSTALLATION 3.1 GENERAL MECHANICAL INSTALLATION General Curtain Dimensions Separation Distance Optical Alignment Reflective Surfaces Systems in Close Proximity Mounting Brackets ELECTRICAL INSTALLATION General Emitter Unit General Test Input Receiver Unit General Operation Safety Outputs Serial Communications 24 2

3 Page 3.4 INITIAL CHECKING AND ALIGNMENT INTERFACE AND AUXILIARY UNITS 4.1 GENERAL Methods of Interfacing BSRSA INTERFACE UNIT General Description Operational Sequence and L.E.D. Status Description Mechanical Electrical Connections Fuses Test Input Monitor/Auxilliary Output Technical Specifications BSRUA-2 INTERFACE UNIT General Description Operational Sequence and LED Status Description Configured For ONE Sensing Unit Configured for TWO Sensing Units Mechanical Electrical Connection Fuses Test Input Technical Specifications SRUB INTERFACE UNIT General Description Operational Sequence and LED Status Description Resetting Options Manual Reset Automatic Reset Mechanical Electrical Connection Fuses Monitor Input (manual mode only) External Reset (manual mode only) Monitor/Auxillary Output SRUB Technical Specifications BPU2 HAND HELD PROGRAMMING UNIT (Blanking Unit) GDC-1 POWER SUPPLY LAT LASER ALIGNMENT TOOL PERIODIC CHECKING, SERVICING AND MAINTENANCE 5.1 PERIODIC CHECKING Commissioning Checks or 12 Monthly Checks Daily/Setting Examination Checking Detection Capability SERVICING MAINTENANCE TECHNICAL SPECIFICATIONS (B Series Emitter & Receiver) 48 3

4 1. GENERAL 1.1 INTRODUCTION Guardstar B Series light curtains are through-beam photo-electric machine guarding devices, designed to protect operators working at or near dangerous machinery. When correctly installed on a suitable machine, the system will detect a person (or part of a person) entering a dangerous area in the vicinity of the machine and will signal the dangerous motion to cease before that person can reach a position where injury could occur. Guardstar B Series light curtains use infra-red technology. A curtain of infra-red light is projected across the dangerous area. Intrusion into this curtain by a person, or part of a person, will be detected by the system. This will cause safety output signals to be generated which will stop the dangerous motion of the machine. B Series systems are fully self-monitoring and meet or exceed worldwide requirements for safeguarding devices used on industrial machines. WARNING The information in this manual relates to the use of the basic B Series light curtain, to provide a basic safety switching device. In some applications a B Series light curtain may be used together with other Tapeswitch equipment to provide additional functions and features. The additional information necessary for the correct use of a B Series light curtain when used with other Tapeswitch equipment is provided within this manual. In such cases, some installation parameters, notably the mounting position of the light curtain in relation to the dangerous part of the machine, can be affected and close attention must be paid to all the information supplied with all equipment. INTERNATIONAL CONSIDERATION: The heritage of the Guardstar B Series system is strongly grounded in international commerce and standards. Guardstar is the registered U.S. trade name for the Guardscan products developed by Guardscan, Ltd., of Chorley, England. Both Guardscan and Tapeswitch are part of the Inductotherm Industries, a private, U.S., industrial group.the Guardstar B Series was developed to meet the published and proposed safety standard for U.S.A., Germany, England, Finland, Sweden as well as the common market unified standard. Guardstar systems are manufactured both in England and the U.S.A. Guardstar B Series has been independently third party tested to IEC by BG, and are certified to this standard (CE approval/certification). Contact Tapeswitch for more details. Tapeswitch can provide additional assistance to customers wishing to use the Guardstar B Series guard in international applications. Some foreign language technical manuals are available. 1.2 PRODUCT APPLICATION TYPICAL APPLICATIONS The high level of safety integrity provided by the B Series light curtains makes them suitable for use on many types of machines including some of those presenting the highest risk. Typical applications are: Pinch point protection Power presses Filter presses Robot assembly and welding cells Die casting machines Injection molding machines Special purpose machinery General automated machinery SUITABILITY The most important factors affecting the suitability of a photo-electric guarding device relate to the machine control system. The machine control system must satisfy the following fundamental requirements: (a) The dangerous motion of the machine must be electrically controllable. (b) The machine response/stopping performance must be adequate and consistent. (c) It must be possible to stop the dangerous motion of the machine at any point in its operation. 4

5 (d) The control system as a whole must be constructed to provide and appropriate category of safety integrity as defined in EN954 Safety of machinery: Principles for the design of safety related control systems. The appropriate category of safety integrity should be determined by performing a risk assessment as described in EN1050 Safety of machinery: Risk assessment. Additional factors which may preclude the use of photoelectric devices include: WARNING The B Series light curtain in itself does not guarantee a category 4 safety system has been achieved. Other factors such as stopping time, separation distance and proper interface all contribute to the overall safety level. A safety system is only as strong as its weakest link and in order to maintain a category 4, all devices in the safety system must be category 4. (e) Risk of injury from thermal or other radiation. (f) An environment likely to adversely affect the efficiency of the photo-electric safety system. (g) A tendency for the machine to eject materials or components which are either potentially hazardous to the operator or which interfere with the operation of the safety device. Photo-electric safety systems may be suitable if additional measures are taken to control the risks associated with factors (e) to (g) e.g. local fixed guards to control ejection. 1.3 PRODUCT STANDARDS Guardstar B Series light curtains meet the requirements of the international standard IEC61496 Safety of machinery: Electro-sensitive protective equipment Parts 1 and 2. Each basic B Series light curtain is a complete Active Opto-electronic Protective Device or AOPD. This means that the infa-red used for detection purposes is generated by the system itself. An AOPD is a particular type of Electro-Sensitive Protective Equipment or ESPE. Both of these terms are defined in IEC61496 Parts 1 and 2. Part 1 applies to all types of ESPE and Part 2 covers the particular requirements for AOPDs. B Series light curtains are Type 4 devices as defined by this standard which means that they are fully selfmonitoring and are therefore suitable for use as part of safety related control systems of category 4 (or below) as defined by EN PRODUCT FEATURES SAFETY INTEGRITY Diverse redundancy. Solid State safety outputs. Fully self-monitoring. Test input for system check. Variety of interface units (optional) EASE OF INSTALLATION No interconnection between curtain units. 24 Vdc operation. Adjustable mounting brackets supplied PROTECTION FROM ENVIRONMENT Immune to ambient light. Immune to xenon beacons and strobes. High level of immunity to vibration. High level of electromagnetic immunity. Enclosures sealed to IP65. Polyester powder coating. 1.5 PRODUCT RANGE GENERAL The B Series light curtains are available in a range of different protected heights and detection capabilities. These two parameters are known by many other names and therefore it may be useful to define them here, as they are intended to be used in this manual. To make this clearer it is also necessary to define two further parameters, detection zone and operating range: Detection Zone: This is the actual curtain of infra-red light generated between the emitter and receiver units within which an appropriately dimensioned object will be reliably detected and, for the B Series, can be considered to be a two dimensional, rectangular plane (see figure 1). 5

6 Operating Range: One dimension of the detection zone rectangle is given by the distance between the emitter and receiver units. This is the operating range (see figure 1). Protected Height: The other dimension of the detection zone rectangle is commonly known as the protected height. The word height has been adopted in the latest standards for this equipment because most curtains are mounted vertically. The protected height is often related to, but is not the same as, the length of the emitter and receiver units (see figure 1). Lenses of adjacent beams Lenses of adjacent beams ØY Object ØY - at least one beam is always totally obscured, therefore object is reliably detected. ØX Object ØX - in this position no beams are totally obscured, therefore object may not be detected. X= Spacing or pitch Y=Detection capability Figure 2 Detection Zone Operating Range Figure 1 Detection Capability: This is the minimum dimension of an opaque object which will be reliably detected anywhere within the detection zone. NOTE: The spacing or pitch of the beams or lenses in a light curtain is not the same as the detection capability. The detection capability is always greater than the spacing or pitch. Spacing or pitch should not be used in the calculation of separation distances (see Figure 2) DETECTION CAPABILITY Protected Height B Series light curtains are available with detection capabilities of 14mm, 30mm, or 70mm PROTECTED HEIGHTS B Series light curtains are available with nominal protected heights as follows: Detection Nominal protected heights capability (in mm and inches) 14mm (1/2 in.) mm ( inches) 30mm (1 3/16 in.) mm ( inches) 70mm (2 3/4 in.) mm ( inches) minimum separation distance is 0.5m. Note: The actual protected height is 8mm greater than the nominal protected height ACCESSORIES Mirror Units A range of mirror units are available to enable a single curtain to be used to guard two or three sides of a machine or to avoid structural obstructions. 6

7 The mirror assembly consists of a high quality silver backed glass mirror adhesively attached to a length of extruded aluminum. Two pivot brackets are bolted to the aluminum extrusion and can be adjusted anywhere along the length for mechanical attachment. The actual length of the mirror is 4 inches (1000mm) larger than the active curtain length to accommodate a wide tolerance for height alignment. All of the necessary hardware is supplied to facilitate mounting to the mounting/floor stands. The dimensions of the pivot brackets, extruded aluminum and overall mirrors are shown below in millimeters. Pivot Bracket X Pivot Brackets (180 Rotation; Distance X is Adjustable) Glass Reflective Surface Overall Length = Protective Height + 4" 180 Rotation in this Plane Supplied with: mm x 40mm extrusion, 100mm larger than protective height silver backed mirror, 100mm larger than protective height pivot joints mm x 40mm end covers mm T slot nuts #12 flat washers mm spring washers mm x 5/8 hex bolts. Extrusion Dimensions Curtain Lengths Mirror Assembly Length P/N 200mm - 8" 300mm - 12" mm - 12" 400mm - 16" mm - 16" 500mm - 20" mm - 24" 700mm - 28" mm 800mm - 32" 900mm - 36" mm - 36" 1000mm - 40" mm 1000mm - 40" 1100mm - 44" mm - 48" 1300mm - 52" mm 6.8mm 1400mm - 56" 1500mm - 60" 0968 For units greater than 56 inch, custom mirrors are available. 7

8 Mounting Stands Model Number Part Number Floor mounting stands are available for use where the guard cannot be mounted directly to the machine. B/8"(208mm)/ B/12"(308mm)/ B/16"(408mm)/ P/N 0957 B/24"(608mm)/ leveling bolts 3/8" holes 5 Supplied with: 1. 5 ft. item 40mm X 40mm extrusion base stand mm X 40mm end cap T slot nuts M M5 X12mm hex head M5 spring lock washers flat washers 5/5.3mm /16 bolts /8 24 x 1/2" hex head. B/32"(808mm)/ B/36"(908mm)/ B/40"(1008mm)/ B/48"(1208mm)/ B/56"(1408mm)/ B/64"(1608mm)/ " 4" 4" 5" B/72"(1808mm)/ B/8"(2008m)/ The mounting stands come with a floor base which a 5 foot tower secures into. The floor base is steel and can be permanently mounted to the floor surface with the pre-drilled mounting holes. The tower is extruded aluminum with slots to allow the light curtain to be positioned anywhere along the 5 foot section. The mounting stands are supplied with all of the necessary hardware to facilitate mounting the standard B Series light curtain. Leveling bolts allow for minor adjustments to the floor stand. 1.6 ORDERING INFORMATION LIGHT CURTAINS Part numbers on the following table should be used for ordering. The units will be marked according to the model as follows: B / XXXX / XX Nominal protected height Detection capability (in millimeters or inches) - (in millimeters) - see section mm, 30mm or 70mm for available sizes B/12"(3008m)/ B/16"(4008m)/ B/24"(608mm)/ B/32"(808mm)/ B/36"(908mm)/ B/40"(1008mm)/ B/48"(1208mm)/ B/24"(608mm)/ B/32"(808mm)/ B/40"(1008mm)/ B/48"(1208mm)/ B/56"(1408mm)/ B/64"(1608mm)/ B/72"(1808mm)/ B

9 1.6.2 CABLE OPTIONS Order cable options using the following part numbers: INTERFACE AND PROGRAMMING UNITS (see electrical interface and operation for technical detail) Order interface and programming units using the following part numbers: Description BSRSA - Metalic Wall Mount Interface BSRUA/2 Part Number Din Rail Mount Interfac e 0951 SRUB - 24VDC Safety Relay Interface GDC1-240/120VAC to +24DC Power Supply BPU2 SRUM LAT Description Part Number Emitter Cable (molded 15 feet) 0972 Emitter Cable (molded 30 feet) 0973 Receiver Cable (molded 15 feet) 0974 Receiver Cable (molded 30 feet) Blanking Unit Muting Controlle r Laser Alignment Too l TECHNICAL DESCRIPTION 2.1 CURTAIN A basic B Series light curtain consists of two units: an emitter unit and a receiver unit. Both units are identical in shape and size. The units are enclosed in a robust extruded aluminum section with reinforced composit end covers. The emitter and receiver units together generate a curtain of infra-red light between them. This curtain is mounted in such a position in relation to the dangerous parts of a machine that a person or part of a person approaching those dangerous parts must first penetrate the curtain. This penetration is detected by the light curtain system and, by means of its output switching devices, the light curtain system causes the dangerous parts to go to a safe state (e.g. by stopping moving parts) before the person can reach them. IMPORTANT From the information above, it can be seen that safe use of a light curtain relies not only on the safety integrity of the curtain itself but also on its proper mechanical and electrical interfacing to the machine. The safety integrity of the light curtain itself is the responsibility of Tapeswitch and the remainder of this section describes the features of the design by which safety integrity is ensured. Proper mechanical and electrical interfacing is the responsibility of the user. Comprehensive information for this purpose is provided in section 3 and 4 of this manual. The emitter unit contains a number of infra-red light emitting diodes (LEDs). The quantity and spacing of these LEDs depends on the protected height and the detection capability of the particular light curtain. The devices are arranged equally spaced in an array. The receiver unit contains a corresponding number of infra-red photodiodes similarly arranged. 9

10 Each LED and photodiode is fitted with a precision lens which gives an evenly intense, slightly diverging beam of infa-red from each LED and a evenly sensitive, slightly converging reception cone into each photodiode. This arrangement provides a high signalto-noise ratio and maximum operating range for the system together with ease of alignment and rejection of extraneous reflected light sources. The function of each LED and photodiode is controlled by its own dedicated, purpose designed ASIC (Application Specific Integrated Circuit). All the circuitry necessary for the operation of an LED or photodiode is contained within this single component, resulting in a very low component count and consequent improvement in reliability for the system. For each LED in the emitter unit there is a corresponding photodiode in the receiver unit, the same relative position within the unit. Each LED/photodiode pair makes a beam and the curtain is made up of a number of such beams, all parallel to each other. (See Figure 3.) Beam 1 Each receiver ASIC in its turn generates an output signal which is proportional to the level of infa-red it receives from its corresponding LED. Signals from other sources, such as background lighting, are filtered out inside the ASIC. There is one micro processor in the emitter unit and two in the receiver unit. All three micro processors perform exhaustive checks on their own hardware and software, prior to and during operation. The two in the receiver unit continually communicate their results to each other such that if a fault occurs in one device the other can shut the system down. In the receiver unit there are two independent switching channels each containing an output signal switching device (OSSD). Each of the two microcontrollers in the receiver unit controls one of these OSSDs and monitors the other. The OSSDs are very robust solid state devices. These devices are intended to be connected directly to the machine control system, a Tapeswitch/Guardscan interface unit or a suitable safety relay such that if one or both of them are in the OFF state, the machine will go to or remain in a safe condition, for example, by stopping dangerous motion or by preventing dangerous motion from starting. 2.2 COMMUNICATIONS The receiver unit incorporates a serial communications port. Various auxiliary Tapeswitch equipment can be connected to this port for the purposes of programming functions within the light curtain and for interrogating the system. No equipment other than Tapeswitch equipment should be connected to this port. Full instructions for the use of this port with auxiliary equipment is provided within this manual. 2.3 TEST INPUT Figure 3 Only one LED and one photodiode are active at any time. The emitter unit runs independently from the receiver unit. There are no connections between the units. The emitter unit activates each of its LEDs in turn and the receiver unit synchronizes with the emitter unit. A pair of terminals is provided across which a pair of normally closed, volt free contacts should be connected. When these contacts are opened the emitter unit will stop scanning, forcing the OSSDs to the OFF state. This input simulates a curtain obstructed condition. NOTE: This input is provided to allow the B Series to be used with machine control systems which need to cycle the safety circuit prior to operation. The B Series system itself does not require this input to be used. If this input is not used it should be jumpered and remain jumpered at all times. 10

11 2.4 INDICATORS The receiver unit has four indicators as shown in Figure 4. The emitter unit has two indicators as shown in Figure 5. A description of each indicator is given in Table 1. Unit Color Description Emitter A mber Lit when power is connected to unit. Red Lit steady when test input is applied. Lit flashing when emitter unit is faulty. A mber Lit when power is connected to unit. G reen Lit when curtain is clear. Receiver Red Yellow Lit brightly when curtain is obstructed. L it dimly when the curtain is clear. Lit flashing when receiver unit is faulty. Lit steady when curtain has been programmed to a state other than no blanking. Table 1 Amber Yellow Amber Red Green Red Figure 4 Receiver Figure 5 Emitter 11

12 3. INSTALLATION 3.1 GENERAL WARNING Guardstar B Series systems are designed to protect operators working at or near dangerous machinery. They can only perform this function if they are correctly fitted and interfaced to a suitable machine. Those persons responsible for the machine must ensure that all persons involved in the installation of the photo-electric safety system have the necessary knowledge, training and experience and that they are fully aware of all laws, rules, regulations and codes of practice pertaining to their task. The attention of the installer is drawn to following general requirements for the installation of a B Series system: (a) The dangerous motion of the machine must be electrically controllable. (b) The machine response/stopping performance must be adequate and consistent. (c) It must be possible to stop the dangerous motion of the machine at any point in its operation, in any operating mode. (d) The control system as a whole must be designed and constructed to provide the appropriate category of safety integrity as defined in EN954 Safety of machinery: Principles for the design of safety related control systems. The appropriate category should be as prescribed in the relevant C type EN standard for the type of machine concerned. In the absence of such a standard the appropriate category of safety integrity should be determined by performing a risk assessment as described in EN1050 Safety of machinery: Risk assessment. (e) Steps must be taken to prevent access to the dangerous parts of the machine from any direction not covered by the photo-electric curtain. Such steps could include fixed or interlocking fences or screens, additional photo-electric devices or pressure sensitive mats. Similar steps should be taken to prevent a person standing between the curtain and the dangerous parts. (f) No devices other than those specified in this manual should be connected to the internally generated power supply of the system. (g) After installation the machine/guard system must be commissioned in accordance with the requirements of section of this manual. (h) Any covers removed during installation must be replaced as soon as possible. (i) After the curtain has been actuated it must not be possible for the machine to restart until a manual control has been operated. This is known as restart interlock. The basic B Series does not provide this function. The function of the basic B Series system is GUARD ONLY i.e. when the curtain is clear the outputs are ON and when the curtain is broken the outputs are OFF. 3.2 MECHANICAL INSTALLATION GENERAL ANSI B gives guidance on the dimensions and positioning of photo-electric safety devices fitted to industrial machines. The main considerations are described below and are illustrated in Figure 6. (a) The appropriate protected height must be selected. The curtain must be of sufficient height such that access to the dangerous parts, from the direction of approach of the operator, is only possible by obstructing the curtain taking into account all possible operator positions. (b) The correct minimum separation distance must be observed. The curtain must be mounted in the correct position in relation to the dangerous parts of the machine to take account of the stopping performance of the machine, the curtain format used and the detection capability of the curtain. (c) Steps must be taken to prevent access to the dangerous parts from any direction not covered by the curtain and to prevent an operator from standing between the curtain and the dangerous parts without obstructing the curtain. Additional mechanical guarding will usually be necessary to achieve this. The physical parameters affecting the positioning are the dimensions of the detection zone of the light curtain (i.e. the protected height and the range) and the minimum separation distance. These are described in the following sections. 12